| Parameter |
Value |
| Designation |
C/2002 L9 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-04-05T23:36:36.622080Z |
| Orbit solution date (soln_date, UTC) |
2026-07-06T12:12:23Z |
| Obs used |
333 |
| NEO |
- |
| M1 |
9.100 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2004-09-23.0000000 |
| e |
0.99841837 |
| q (au) |
7.033003 |
| a (au) |
4446.692041 |
| i (deg) |
68.442151 |
| Ω (om, deg) |
110.451458 |
| ω (w, deg) |
231.428640 |
| M (ma, deg) |
0.000565 |
Magnitude
Scatter + Global Linear
$$
M_a = (-0.517 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-0.517 |
| n |
6.000 |
| gf |
0.908 |
| gb |
-0.957 |
| k |
1.000 |
| δ90 |
5.625 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2002-06-06 |
2003-10-20 |
+1.1441 |
-1.109 |
| 2004-06-23 |
2006-01-02 |
+6.0710 |
-5.664 |
| 2006-01-02 |
2007-01-11 |
+17.2877 |
-15.483 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
07:36:42.31 |
+22:41:22.8 |
HIP 37121 |
24.86 |
| 2026-09-20 12:00 |
07:36:43.79 |
+22:41:24.4 |
HIP 37121 |
24.70 |
| 2026-09-21 00:00 |
07:36:45.24 |
+22:41:25.9 |
HIP 37121 |
24.55 |
| 2026-09-21 12:00 |
07:36:46.67 |
+22:41:27.6 |
HIP 37121 |
24.41 |
| 2026-09-22 00:00 |
07:36:48.07 |
+22:41:29.3 |
HIP 37121 |
24.27 |
| 2026-09-22 12:00 |
07:36:49.45 |
+22:41:31.1 |
HIP 37121 |
24.14 |
| 2026-09-23 00:00 |
07:36:50.80 |
+22:41:32.9 |
HIP 37121 |
24.02 |
| 2026-09-23 12:00 |
07:36:52.13 |
+22:41:34.8 |
HIP 37121 |
23.90 |
| 2026-09-24 00:00 |
07:36:53.43 |
+22:41:36.7 |
HIP 37121 |
23.79 |
| 2026-09-24 12:00 |
07:36:54.71 |
+22:41:38.7 |
HIP 37121 |
23.69 |
| 2026-09-25 00:00 |
07:36:55.96 |
+22:41:40.8 |
HIP 37121 |
23.59 |
| 2026-09-25 12:00 |
07:36:57.19 |
+22:41:42.9 |
HIP 37121 |
23.50 |
| 2026-09-26 00:00 |
07:36:58.39 |
+22:41:45.1 |
HIP 37121 |
23.42 |
| 2026-09-26 12:00 |
07:36:59.57 |
+22:41:47.3 |
HIP 37121 |
23.34 |
| 2026-09-27 00:00 |
07:37:00.72 |
+22:41:49.7 |
HIP 37121 |
23.27 |
| 2026-09-27 12:00 |
07:37:01.84 |
+22:41:52.0 |
HIP 37121 |
23.21 |
| 2026-09-28 00:00 |
07:37:02.94 |
+22:41:54.5 |
HIP 37121 |
23.15 |
| 2026-09-28 12:00 |
07:37:04.02 |
+22:41:57.0 |
HIP 37121 |
23.10 |
| 2026-09-29 00:00 |
07:37:05.07 |
+22:41:59.5 |
HIP 37121 |
23.05 |
| 2026-09-29 12:00 |
07:37:06.09 |
+22:42:02.2 |
HIP 37121 |
23.01 |
| 2026-09-30 00:00 |
07:37:07.09 |
+22:42:04.8 |
HIP 37121 |
22.98 |
| 2026-09-30 12:00 |
07:37:08.06 |
+22:42:07.6 |
HIP 37121 |
22.95 |
| 2026-10-01 00:00 |
07:37:09.00 |
+22:42:10.4 |
HIP 37121 |
22.92 |
| 2026-10-01 12:00 |
07:37:09.92 |
+22:42:13.3 |
HIP 37121 |
22.90 |
| 2026-10-02 00:00 |
07:37:10.81 |
+22:42:16.2 |
HIP 37121 |
22.89 |
| 2026-10-02 12:00 |
07:37:11.68 |
+22:42:19.2 |
HIP 37121 |
22.88 |
| 2026-10-03 00:00 |
07:37:12.51 |
+22:42:22.3 |
HIP 37121 |
22.87 |
| 2026-10-03 12:00 |
07:37:13.33 |
+22:42:25.4 |
HIP 37121 |
22.87 |
| 2026-10-04 00:00 |
07:37:14.11 |
+22:42:28.6 |
HIP 37121 |
22.87 |
| 2026-10-04 12:00 |
07:37:14.87 |
+22:42:31.9 |
HIP 37121 |
22.88 |
| 2026-10-05 00:00 |
07:37:15.60 |
+22:42:35.2 |
HIP 37121 |
22.89 |
| 2026-10-05 12:00 |
07:37:16.31 |
+22:42:38.6 |
HIP 37121 |
22.91 |
| 2026-10-06 00:00 |
07:37:16.98 |
+22:42:42.1 |
HIP 37121 |
22.93 |
| 2026-10-06 12:00 |
07:37:17.63 |
+22:42:45.6 |
HIP 37121 |
22.95 |
| 2026-10-07 00:00 |
07:37:18.26 |
+22:42:49.2 |
HIP 37121 |
22.97 |
| 2026-10-07 12:00 |
07:37:18.85 |
+22:42:52.8 |
HIP 37121 |
23.00 |
| 2026-10-08 00:00 |
07:37:19.42 |
+22:42:56.6 |
HIP 37121 |
23.04 |
| 2026-10-08 12:00 |
07:37:19.96 |
+22:43:00.4 |
HIP 37121 |
23.07 |
| 2026-10-09 00:00 |
07:37:20.47 |
+22:43:04.2 |
HIP 37121 |
23.11 |
| 2026-10-09 12:00 |
07:37:20.96 |
+22:43:08.1 |
HIP 37121 |
23.15 |
| 2026-10-10 00:00 |
07:37:21.42 |
+22:43:12.1 |
HIP 37121 |
23.20 |
| 2026-10-10 12:00 |
07:37:21.85 |
+22:43:16.2 |
HIP 37121 |
23.25 |
| 2026-10-11 00:00 |
07:37:22.25 |
+22:43:20.3 |
HIP 37121 |
23.30 |